This review aims to describe a novel method in the field of electromyography (EMG), established and improved upon in the last three decades that is able to observe specific parameters of muscle units (MUs). This concept is called the decomposition method, based on its ability to decompose a surface EMG signal to describe muscle activity on the level of individual muscle units in contrast to the level of the whole muscle, as is customary for regular surface electromyography. We provide a brief overview of its history, constituent parts regarding both hardware and software and possible applications. We also acknowledge the state of the research, regarding the background of the decomposition algorithm, the main software component responsible for identifying individual motor units and their parameters. As a result of the ability to describe the behavior of individual motor units during muscle contractions, key concepts in neuromuscular physiology have been put forward, pertaining to the hierarchy of MUs during their recruitment. Together with the recent application for cyclic contractions and gait, the decomposition method is beginning to open up wider possibilities of enquiry.
- MeSH
- algoritmy MeSH
- elektromyografie * metody MeSH
- kosterní svaly * fyziologie MeSH
- lidé MeSH
- motorické neurony fyziologie MeSH
- počítačové zpracování signálu MeSH
- recruitment (neurofyziologie) * fyziologie MeSH
- svalová kontrakce * fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND AND OBJECTIVES: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disease primarily affecting the peripheral nervous system. However, several noncontrolled studies have suggested concomitant inflammatory CNS demyelination similar to multiple sclerosis. The aim of this study was to investigate an involvement of the visual pathway in patients with CIDP. METHODS: In this prospective cross-sectional study, we used high-resolution spectral-domain optical coherence tomography to compare the thickness of the peripapillary retinal nerve fiber layer and the deeper macular retinal layers as well as the total macular volume (TMV) in 22 patients with CIDP and 22 age-matched and sex-matched healthy control (HC) individuals. Retinal layers were semiautomatically segmented by the provided software and were correlated with clinical measures and nerve conduction studies. RESULTS: In patients with CIDP compared with healthy age-matched and sex-matched controls, we found slight but significant volume reductions of the ganglion cell/inner plexiform layer complex (CIDP 1.86 vs HC 1.95 mm3, p = 0.015), the retinal pigment epithelium (CIDP 0.38 vs HC 0.40 mm3, p = 0.02), and the TMV (CIDP 8.48 vs HC 8.75 mm3, p = 0.018). The ganglion cell layer volume and motor nerve conduction velocity were positively associated (B = 0.002, p = 0.02). DISCUSSION: Our data reveal subtle retinal neurodegeneration in patients with CIDP, providing evidence for visual pathway involvement, detectable by OCT. The results need corroboration in independent, larger cohorts.
- MeSH
- chronická zánětlivá demyelinizační polyneuropatie diagnostické zobrazování patologie patofyziologie MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- nervové vedení fyziologie MeSH
- optická koherentní tomografie MeSH
- prospektivní studie MeSH
- průřezové studie MeSH
- retina diagnostické zobrazování patologie MeSH
- senioři MeSH
- zrakové dráhy diagnostické zobrazování patologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
In this paper we investigate the rate coding capabilities of neurons whose input signal are alterations of the base state of balanced inhibitory and excitatory synaptic currents. We consider different regimes of excitation-inhibition relationship and an established conductance-based leaky integrator model with adaptive threshold and parameter sets recreating biologically relevant spiking regimes. We find that given mean post-synaptic firing rate, counter-intuitively, increased ratio of inhibition to excitation generally leads to higher signal to noise ratio (SNR). On the other hand, the inhibitory input significantly reduces the dynamic coding range of the neuron. We quantify the joint effect of SNR and dynamic coding range by computing the metabolic efficiency-the maximal amount of information per one ATP molecule expended (in bits/ATP). Moreover, by calculating the metabolic efficiency we are able to predict the shapes of the post-synaptic firing rate histograms that may be tested on experimental data. Likewise, optimal stimulus input distributions are predicted, however, we show that the optimum can essentially be reached with a broad range of input distributions. Finally, we examine which parameters of the used neuronal model are the most important for the metabolically efficient information transfer.
- MeSH
- adenosintrifosfát metabolismus MeSH
- akční potenciály fyziologie MeSH
- excitační postsynaptické potenciály fyziologie MeSH
- membránové potenciály fyziologie MeSH
- modely neurologické * MeSH
- nervové vedení fyziologie MeSH
- nervový přenos fyziologie MeSH
- nervový útlum fyziologie MeSH
- neurony fyziologie MeSH
- počítačová simulace MeSH
- poměr signál - šum MeSH
- výpočetní biologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenosintrifosfát MeSH
OBJECTIVES: Occupational carpal tunnel syndrome (CTS) due to upper extremity overuse has in recent years been the most commonly recognized occupational disease in the Czech Republic and its prevalence has steadily increased. This pilot observation aimed to assess the effects of exercise techniques and oral enzyme therapy in automotive plant workers with early CTS. PATIENTS AND METHODS: The observation comprised automotive plant assembly line workers in whom nerve conduction study revealed incipient CTS. The subjects were divided into three groups: a group practicing exercise techniques (exercising; N=15), a group receiving oral enzyme therapy (N=16), and a group of controls (N=14). Subjects in the control group were only observed without any specific intervention, which is a common procedure in incipient CTS. Throughout 9-week observation, the workers did their jobs. Prior to and after that period, the workers' CTS-related symptoms were ascertained through structured interviews with a physician and the following median nerve parameters were measured: sensory conduction velocity (SCV) and distal motor latency (DML). RESULTS: In both the exercise and enzyme therapy groups, statistically significant decreases in the total score for symptoms were achieved (p<0.0001), unlike controls. On final examination, both treated groups demonstrated significantly increased SCV as compared with the initial values (p=0.00013 and p<0.0001, respectively); in controls, the mean SCV did not significantly change. Similarly, a statistically significant shortening of DML was noted in the enzyme therapy group (p=0.008). CONCLUSION: The results showed the efficiency of both exercise and oral enzyme therapy in incipient CTS. These methods may be recommended for preventing more severe forms of CTS.
- MeSH
- dospělí MeSH
- elektromyografie MeSH
- enzymoterapie * MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci z povolání diagnostické zobrazování patofyziologie terapie MeSH
- nervové vedení fyziologie MeSH
- nervus medianus patofyziologie MeSH
- syndrom karpálního tunelu diagnostické zobrazování patofyziologie terapie MeSH
- techniky fyzikální terapie MeSH
- terapie cvičením * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Diabetic peripheral neuropathy (DPN) is a common complication of diabetes with potential severe consequences. Its pathogenesis involves hyperglycemia-linked mechanisms, which may include changes in the expression of neurotrophic growth factors. We analyzed the expression of 29 factors potentially related to nerve degeneration and regeneration in skin biopsies from 13 type 1 diabetic pancreas and kidney recipients with severe DPN including severe depletion of intraepidermal nerve fibers (IENF) in lower limb skin biopsies (group Tx1 1st examination). The investigation was repeated after a median 28-month period of normoglycemia achieved by pancreas transplantation (group Tx1 2nd examination). The same tests were performed in 13 stable normoglycemic pancreas and kidney recipients 6-12 years posttransplantation (group Tx2), in 12 matched healthy controls (group HC), and in 12 type 1 diabetic subjects without severe DPN (group DM). Compared to DM and HC groups, we found a significantly higher (p < 0.05-0.001) expression of NGF (nerve growth factor), NGFR (NGF receptor), NTRK1 (neurotrophic receptor tyrosine kinase 1), GDNF (glial cell-derived neurotrophic factor), GFRA1 (GDNF family receptor alpha 1), and GFAP (glial fibrillary acidic protein) in both transplant groups (Tx1 and Tx2). Enhanced expression of these factors was not normalized following the median 28-month period of normoglycemia (Tx1 2nd examination) and negatively correlated with IENF density and with electrophysiological indices of DPN (vibration perception threshold, electromyography, and autonomic tests). In contrast to our expectation, the expression of most of 29 selected factors related to neural regeneration was comparable in subjects with severe peripheral nerve fiber depletion and healthy controls and the expression of six factors was significantly upregulated. These findings may be important for better understanding the pathophysiology of nerve regeneration and for the development of intervention strategies.
- MeSH
- diabetické neuropatie metabolismus MeSH
- dospělí MeSH
- kůže inervace metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- nervová vlákna metabolismus MeSH
- nervové vedení fyziologie MeSH
- neurotrofní faktory metabolismus MeSH
- regenerace nervu fyziologie MeSH
- transplantace ledvin * MeSH
- transplantace slinivky břišní * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- neurotrofní faktory MeSH
Traumatic injuries to peripheral nerves are frequent, however, specific pharmacological treatments are currently lacking. Curcumin has antioxidant, anti-inflammatory and neuroprotective properties but high oral doses are required for therapeutic use, particularly due to its low bioavailability. The aim of the present study was to investigate the effects of local and continuous treatment using low curcumin doses on functional recovery and nerve regeneration after rat sciatic nerve crush (SNC). Curcumin was administered by osmotic pumps with a catheter delivering the drug at the injury site (0.2 mg/day for 4 weeks). Functionally, early improvements in mechanical sensitivity, finger spacing of the injured paw, skilful walking and grip strength were observed in curcumin-treated animals. The curcumin treatment increased expression of compact myelin proteins (MPZ and PMP22), myelin sheath thickness and, correspondingly, increased motor and sensitive nerve conduction velocity. Microscopic analysis of gastrocnemius muscle indicated a curcumin-induced decrease in neurogenic lesions. Curcumin treatment reduced the production of reactive oxygen species (ROS) (which were notably produced by macrophages), lipid peroxidation and increased expression of transcription factor Nrf2. In silico analyses indicated that curcumin combines all the characteristics required to be an efficient lipid peroxidation inhibitor at the heart of biological membranes, hence protecting their degradation due to ROS. This antioxidant capacity is likely to contribute to the beneficial effects of curcumin after SNC injury. These results demonstrate that, when administrated locally, low doses of curcumin represent a promising therapy for peripheral nerve regeneration.
- Klíčová slova
- Curcumin, Myelin, Oxidative stress, Sciatic nerve crush,
- MeSH
- antioxidancia farmakologie MeSH
- drtivá poranění farmakoterapie patologie patofyziologie MeSH
- faktor 2 související s NF-E2 metabolismus MeSH
- kosterní svaly účinky léků patologie patofyziologie MeSH
- kultivované buňky MeSH
- kurkumin farmakologie MeSH
- náhodné rozdělení MeSH
- nervové vedení účinky léků MeSH
- nervus ischiadicus účinky léků zranění patologie patofyziologie MeSH
- neuroprotektivní látky farmakologie MeSH
- obnova funkce účinky léků fyziologie MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- potkani Sprague-Dawley MeSH
- remyelinizace účinky léků fyziologie MeSH
- simulace molekulární dynamiky MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- faktor 2 související s NF-E2 MeSH
- kurkumin MeSH
- neuroprotektivní látky MeSH
- Nfe2l2 protein, rat MeSH Prohlížeč
UNLABELLED: The last eight survivors of 80 workers accidentally exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during production of herbicides based on trichlorophenoxyacetic acid in 1965-1967 in a chemical factory were followed. All were men, mean age 72.4 ± 1.3 years. Their current median TCDD blood level was 112 (46-390) pg/g lipids. Neurological examination revealed central nervous system impairment in all individuals and signs of polyneuropathy in 87.5%, which was confirmed by a nerve conduction study (NCS) in 75%. A Lanthony test demonstrated acquired dyschromatopsia in 87.5% of the patients, with deterioration of mean colour confusion index (CCI) from 1.52 ± 0.39 in 2010 to 1.73 ± 0.41 in 2016. Single-photon emission computer tomography (SPECT) of the brain showed focal reduction of perfusion in various brain locations in all patients and worsening in six patients. Visual-evoked potentials (VEP) was abnormal in 62.6% of individuals. Most patients complained of psychological problems. The neuropsychological test battery showed most positive impairments in the Trail Making Test evaluating processing speed (average level in the range of mild neurocognitive impairment), which correlated with mean CCI (p < 0.05). CONCLUSION: Fifty years after exposure, blood levels of TCDD are still 10 times higher than the general population. NCS, VEP, Lanthony test and SPECT findings deteriorated from examination of these patients in 2004 and in 2010. The total of abnormal tests per patient in 2016 is very high. Minor differences among patients and their reduced count may explain why the number of impairments in 2016 does not correlate with TCDD blood level.
- MeSH
- časové faktory MeSH
- chemický průmysl * MeSH
- herbicidy škodlivé účinky krev chemická syntéza MeSH
- hygiena práce * MeSH
- jednofotonová emisní výpočetní tomografie MeSH
- kognice účinky léků MeSH
- lidé MeSH
- mozek diagnostické zobrazování účinky léků patofyziologie MeSH
- mozkový krevní oběh účinky léků MeSH
- nervové vedení účinky léků MeSH
- neurologické vyšetření MeSH
- neuropsychologické testy MeSH
- neurotoxické syndromy diagnóza etiologie patofyziologie psychologie MeSH
- perfuzní zobrazování metody MeSH
- polychlorované dibenzodioxiny škodlivé účinky krev chemická syntéza MeSH
- polyneuropatie chemicky indukované diagnóza patofyziologie MeSH
- pracovní expozice škodlivé účinky MeSH
- pracovní nehody * MeSH
- senioři MeSH
- vidění barevné účinky léků MeSH
- zrakové evokované potenciály účinky léků MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- herbicidy MeSH
- polychlorované dibenzodioxiny MeSH
- MeSH
- alemtuzumab škodlivé účinky MeSH
- dospělí MeSH
- elektromyografie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- nemoci periferního nervového systému chemicky indukované diagnostické zobrazování MeSH
- nervové vedení účinky léků fyziologie MeSH
- protinádorové látky imunologicky aktivní škodlivé účinky MeSH
- roztroušená skleróza diagnostické zobrazování farmakoterapie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
- Názvy látek
- alemtuzumab MeSH
- protinádorové látky imunologicky aktivní MeSH
INTRODUCTION: A-waves, which are observed following the M-wave during motor nerve conduction studies (NCS), are late responses that are frequently found in many types of neurogenic disorders. However, A-waves are also common in healthy individuals, where their significance remains unclear. The aim of this study was to examine whether the occurrence of A-waves does in fact represent an increased risk for the future development of changes upon NCS or needle electromyography (EMG) in the corresponding nerve. METHODS: Nerve conduction studies/needle electromyography findings at control examination were evaluated in relation to the occurrence of initial A-waves in 327 individuals who had undergone repeated NCS/EMG examination and exhibited normal initial findings, with or without the occurrence of A-waves as the only acceptable abnormality. RESULTS: The odds ratio, which reflects the predictive power of the occurrence of A-waves at the initial testing for the development of an abnormality (neuropathy or radiculopathy) at the follow-up examination, ranged from 2.7 (p = .041) in the tibial nerve and 3.9 (p = .034) in peroneal one, to 30.0 (p = .002) in the ulnar nerve. CONCLUSIONS: A-waves constitute an initial abnormality in all nerves, and they may be predictive for the future development of broader NCS/EMG abnormalities in the corresponding nerve.
- Klíčová slova
- A‐wave, F‐wave, electromyography, late response, nerve conduction study, neurography, neuropathy,
- MeSH
- akční potenciály MeSH
- dospělí MeSH
- elektromyografie metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci periferního nervového systému diagnóza patofyziologie MeSH
- nervové vedení fyziologie MeSH
- neurologické vyšetření metody MeSH
- periferní nervy patofyziologie MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Anesthetic and surgical procedures and an electrophysiological method were developed for recording nerve conduction velocity (NCV) of CNS fibers in the murine spinal cord. Under intravenous anesthesia and artificial ventilation the lumbar spinal cord segments L1 to L4 and dorsal roots L3 to L5 on the left side were exposed by laminectomy. After stimulation of the dorsal root L4, a compound action potential (CAP) was recorded at the ipsilateral left fasciculus gracilis at the spinal cord level L1. The latency from stimulation to the CAP together with the measured distance between the electrodes was used for the determination of the NCV. NCV of the fastest fibers in the fasciculus gracilis was observed to be approximately 28 m/s. Reversible decrease of the NCV was measured, in vivo, under general hypothermia. The technique described serves for in vivo electrophysiological investigations of spinal central fibers in wildtype and mutant mice.
